Adsorption of Pb (II) Using Partially Deproteinated Water Hyacinth (Eichhornia crassipes) Roots

• Published in: IOP conference series. Earth and environmental science Vol. 563; no. 1; pp. 12009 - 12018
• Main Authors: Nieva, A.D., Ang, M.D.D., Hipolito, H.G., Calderon, E.J., Pamintuan, K.R.S.
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.11.2020
• Subjects: Adsorption; Ambient temperature; Aquatic plants; Aqueous solutions; Bonding strength; Centrifugation; Chemical bonds; Deionization; Eichhornia crassipes; Fibers; Floating plants; Functional groups; Heavy metals; Industrial pollution; Industrial wastes; Industrial wastewater; Ions; Lead; Metal industry wastewaters; Organic matter; Pollutant removal; Pollutants; Roots; Sorbents; Treated water; Wastewater; Wastewater pollution; Water hyacinths
• ISSN: 1755-1307; 1755-1315
• DOI: 10.1088/1755-1315/563/1/012009

Water hyacinth (Eichhornia crassipes) is known to be an effective biosorbent capable of removing pollutants of industrial wastewater effluents, particularly heavy metals. This study determined and compared the effectiveness of removing Pb2+ in a lead-containing aqueous solution using untreated and treated water hyacinth roots. The treated biosorbent was the heavy organic matter that settled from the extraction of water-soluble portions of the water hyacinth roots upon centrifugation of the water hyacinth and deionized water mixture for 1 hour at ambient temperature. The treatment of the biosorbent resulted to less functional groups but more exposed fibers for which the Pb2+ ions can adhere to. At a 24-hour equilibrium time, it was determined that the untreated biosorbent gave higher adsorption capacity of 0.743 mg/g as compared to the 0.653 mg/g capacity of the treated biosorbent. However, it was observed that in a 2-hour equilibrium time, similar adsorption capacities were obtained at 0.75 mg/g for both biosorbents. The kinetic study reveals that saturation of the biosorbents was observed within a 2-hour contact time. At prolonged adsorption time, the decrease in adsorption capacity of the treated biosorbent was due to the adsorption-desorption process that occurred at the saturated sorbent surfaces, whereby the attached Pb2+ was released and re-attached interchangeably. The loss of functional groups in the treated biosorbent resulted to less strong bonds from chemical adsorption and thus in a higher contact time, the loosely binded Pb2+ ions return to the aqueous phase.